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| author | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2016-06-21 12:38:25 -0400 |
|---|---|---|
| committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2016-07-19 16:11:50 -0400 |
| commit | 2b011b64d8ca5f3f7b26806aeb77939ff7703c06 (patch) | |
| tree | 35f394b019f3afd3b32e9ba1b9f21399ce1fc7f2 /src | |
| parent | 099fc05ebf443e2bcc8c5ab9c627c86ec1e743e0 (diff) | |
| download | libopus-2b011b64d8ca5f3f7b26806aeb77939ff7703c06.tar.gz | |
Moving FEC decision to the Opus encoder level (from SILK level)
Diffstat (limited to 'src')
| -rw-r--r-- | src/opus_encoder.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/src/opus_encoder.c b/src/opus_encoder.c index 792fbf6b..93badd46 100644 --- a/src/opus_encoder.c +++ b/src/opus_encoder.c @@ -156,6 +156,14 @@ static const opus_int32 mode_thresholds[2][2] = { { 36000, 16000}, /* stereo */ }; +static const opus_int32 fec_thresholds[] = { + 12000, 1000, /* NB */ + 14000, 1000, /* MB */ + 16000, 1000, /* WB */ + 20000, 1000, /* SWB */ + 22000, 1000, /* FB */ +}; + int opus_encoder_get_size(int channels) { int silkEncSizeBytes, celtEncSizeBytes; @@ -943,6 +951,39 @@ opus_val16 compute_stereo_width(const opus_val16 *pcm, int frame_size, opus_int3 return EXTRACT16(MIN32(Q15ONE, MULT16_16(20, mem->max_follower))); } +static int decide_fec(int useInBandFEC, int PacketLoss_perc, int last_fec, int mode, int *bandwidth, opus_int32 rate) +{ + int orig_bandwidth; + if (!useInBandFEC || PacketLoss_perc == 0 || mode == MODE_CELT_ONLY) + return 0; + orig_bandwidth = *bandwidth; + for (;;) + { + opus_int32 hysteresis; + opus_int32 LBRR_rate_thres_bps; + /* Compute threshold for using FEC at the current bandwidth setting */ + LBRR_rate_thres_bps = fec_thresholds[2*(*bandwidth - OPUS_BANDWIDTH_NARROWBAND)]; + hysteresis = fec_thresholds[2*(*bandwidth - OPUS_BANDWIDTH_NARROWBAND) + 1]; + if (last_fec == 1) LBRR_rate_thres_bps -= hysteresis; + if (last_fec == 0) LBRR_rate_thres_bps += hysteresis; + LBRR_rate_thres_bps = silk_SMULWB( silk_MUL( LBRR_rate_thres_bps, + 125 - silk_min( PacketLoss_perc, 25 ) ), SILK_FIX_CONST( 0.01, 16 ) ); + /* If loss <= 5%, we look at whether we have enough rate to enable FEC. + If loss > 5%, we decrease the bandwidth until we can enable FEC. */ + if (rate > LBRR_rate_thres_bps) + return 1; + else if (PacketLoss_perc <= 5) + return 0; + else if (*bandwidth > OPUS_BANDWIDTH_NARROWBAND) + (*bandwidth)--; + else + break; + } + /* Couldn't find any bandwidth to enable FEC, keep original bandwidth. */ + *bandwidth = orig_bandwidth; + return 0; +} + static int compute_silk_rate_for_hybrid(int rate, int bandwidth, int frame20ms, int vbr) { int entry; int i; @@ -1543,6 +1584,8 @@ opus_int32 opus_encode_native(OpusEncoder *st, const opus_val16 *pcm, int frame_ st->bandwidth = IMIN(st->bandwidth, st->detected_bandwidth); } #endif + st->silk_mode.LBRR_coded = decide_fec(st->silk_mode.useInBandFEC, st->silk_mode.packetLossPercentage, + st->silk_mode.LBRR_coded, st->mode, &st->bandwidth, equiv_rate); celt_encoder_ctl(celt_enc, OPUS_SET_LSB_DEPTH(lsb_depth)); /* CELT mode doesn't support mediumband, use wideband instead */ |